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RSNA Publications Online
between anteriot and middle scalene and then then by subclavian artery, I have still not seen brachial plexopathy, even when it routinely gets 70 gy in head and neck cancer with involved nodes, before the era of contouring
 
nkmiami said:
RSNA Publications Online
between anteriot and middle scalene and then then by subclavian artery, I have still not seen brachial plexopathy, even when it routinely gets 70 gy in head and neck cancer with involved nodes, before the era of contouring
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Agreed. I think 72-76 point dose is a realistic tolerance, maybe even higher.

Would be much more concerned about tumor progression in a large h&n LN or surgically-inoperable pancoast tumor vs plexopathy when going to 66-70 Gy

Brachial plexopathy in apical non-small cell lung cancer treated with definitive radiation: dosimetric analysis and clinical implications. - PubMed - NCBI
 
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I like this article/atlas. PMID 24138919

Ideally you would use contrast. Generally you can’t see the brachial plexus (aside from a dedicated MRI) and you contour where it is located based upon muscles, vessels and neural foramen. For head and neck cancers it is best to use a dedicated head and neck atlas since the arm position is different (it is not a major difference in BP though)
 
Try to keep V70<10%
If you're not treating anything in the low neck to 70, I'm not sure you need to constrain it. My impression from the literature is that it will take 60 without a problem.
 
there was an a-- at a cancer center in Houston who used to say you couldnt treat the brachial plexus past 60 for low neck nodes, so you would stop there and have a neck dissection (which is probably worse for the brachial plexus and swallowing imo)
 
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Brachial plexopathy after prescribed 66-70 Gy for head and neck cancer does occur. I've seen it on my own patients, and it can be pretty detrimental to QOL.
 
I inherited a large head and neck service at NCI center, and never saw or heard of it one, and it was never contoured in the early 2000s. I also remember speaking with Paul Busse at MGH at the time, and I believe he said he had not really come across it either. In terms of fibrosis, there certainly is more fibrosis after 60 Gy and surgery than just 70 and radiation, and there may be detreminetal swallowing and nuerololigcal effects
Factors associated with severe late toxicity after concurrent chemoradiation for locally advanced head and neck cancer: an RTOG analysis. - PubMed - NCBI

It is possible if you really examine pts, there is a some slight strength deficit in a nerve branch, but clininically meaningful fulminanet plexopathy I have only seen from tumor.
 
nkmiami said:
RSNA Publications Online
between anteriot and middle scalene and then then by subclavian artery, I have still not seen brachial plexopathy, even when it routinely gets 70 gy in head and neck cancer with involved nodes, before the era of contouring
Click to expand...

We were somewhat cavalier in residency about this and they didn't even draw the plexus in head and neck cases. But I think we need to take a bit more care about the plexus constraint. Patient will live a long time and I have seen more patients in followup now from 3D era where they had plexopathy related issues (not terrible enough that they needed amputation or something, but still pretty uncomfortable). It doesn't mean youre not getting coverage there, you're merely pushing dose to avoid the structure where you can and thereby reducing the integral dose.
 
It would be interesting to see how many of these cases had neck dissections...
 
Agree, ones I've personally caused were CTCAE G2 and G3. Tumor control trumps risk of plexopathy. It's just meticulous contouring and planning will decrease the risk of brachial plexopathy and help a few patients.

nkmiami said:
I inherited a large head and neck service at NCI center, and never saw or heard of it one, and it was never contoured in the early 2000s. I also remember speaking with Paul Busse at MGH at the time, and I believe he said he had not really come across it either. In terms of fibrosis, there certainly is more fibrosis after 60 Gy and surgery than just 70 and radiation, and there may be detreminetal swallowing and nuerololigcal effects
Factors associated with severe late toxicity after concurrent chemoradiation for locally advanced head and neck cancer: an RTOG analysis. - PubMed - NCBI

It is possible if you really examine pts, there is a some slight strength deficit in a nerve branch, but clininically meaningful fulminanet plexopathy I have only seen from tumor.
Click to expand...
 
I have also seen quite a bit of re-irradiation and there was and RTOG re-irradiation trial for head and neck.
 
seper said:
Agree, ones I've personally caused were CTCAE G2 and G3. Tumor control trumps risk of plexopathy. It's just meticulous contouring and planning will decrease the risk of brachial plexopathy and help a few patients.
Click to expand...

definitely tumor control trumps plexopathy risk. I feel that there are a lot of people out there though that will use statement that and just not do everything they can to reduce risk. are you really gonna recur in this small area of the low neck where the plexus is that you allow to get 60 but not 63? But why is the plexus constraint just ignored - taking the full plexus to 60 or above without trying to spare parts of it will run the risk of toxicity. We should utilize the capabilities of IMRT
 
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point taken, but it is extremely rare in head and cancer...its been discussed on mednet... Most would just contour it and avoid hot spots in it.
 
For C5 and C6 roots, simply contouring them and adding to the IMRT optimization list cuts dose by a lot without compromising GTV coverage (try it).
 
If there's gross tumor next to the plexus you treat the tumor and skimp on PTV a little bit maybe and focus on line-up with daily IGRT there to be as accurate as possible.

I think the RTOG contouring guidelines are fine: http://www.redjournal.org/article/S0360-3016(08)00416-1/abstract

Just contour the general course and avoid 66 as feasible, if your prescription dose is higher right next to it then avoid 105% hotspots in the plexus contour.

I would not underdose GTV or CTV to meet Plexus constraints.
 
I have a NSCLC case at the apex of the lung right now we're planning for which I contoured the plexus. We're treating with SBRT, so I am worried about dose just superior to the lesion, but we should be able to avoid the plexus. Has anyone seen any plexopathy with SBRT? I've treated a few patients with tumors in this location and so far, so good. I haven't seen, either in practice or in training, brachial plexopathy after chemoRT for H+N cancer, and I think it's very rare.

I recently treated a family practice physician who had a solitary recurrence IN the brachial plexus for breast cancer, in-field (of course) 15 years down the line after whole breast + regional RT for breast cancer. I made our local friendly IR doc biopsy it, as there was no chance I was treating it without path. Came back as IDC, so I treated it to 66 Gy in 2 Gy fractions. Responded very well and she's NED 2 years out now with no s/sx of plexopathy...yet. If she hadn't been treated before I might have taken it to 70 Gy. Hopefully she'll do well. Stay tuned.
 
There's dose constraints for plexus for 3, 5, and 15 fraction regimens available. The old breast cancer studies suggested that anything more than 45-50Gy in 2.75-3 Gy fractions had upwards of double digit percentages of brachial plexopathy.

If I couldn't meet SBRT constraints for plexopathy, I wouldn't treat with SBRT. We've had apical lung tumors that we abort 45/15 for because of brachial plexus concerns.
 
OTN said:
I have a NSCLC case at the apex of the lung right now we're planning for which I contoured the plexus. We're treating with SBRT, so I am worried about dose just superior to the lesion, but we should be able to avoid the plexus. Has anyone seen any plexopathy with SBRT? I've treated a few patients with tumors in this location and so far, so good. I haven't seen, either in practice or in training, brachial plexopathy after chemoRT for H+N cancer, and I think it's very rare.

I recently treated a family practice physician who had a solitary recurrence IN the brachial plexus for breast cancer, in-field (of course) 15 years down the line after whole breast + regional RT for breast cancer. I made our local friendly IR doc biopsy it, as there was no chance I was treating it without path. Came back as IDC, so I treated it to 66 Gy in 2 Gy fractions. Responded very well and she's NED 2 years out now with no s/sx of plexopathy...yet. If she hadn't been treated before I might have taken it to 70 Gy. Hopefully she'll do well. Stay tuned.
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I have also retreated the brachial plexus in this situation without plexopathy.
Pulsed reduced dose-rate radiotherapy: a novel locoregional retreatment strategy for breast cancer recurrence in the previously irradiated chest wa... - PubMed - NCBI
 
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